1. Field of the Invention
The present invention relates generally to devices for electropolishing the inner surface of metal tubes and more particularly to such devices which utilize flexible electrodes drawn through the tube.
2. Description of the Prior Art
Metal tubing that is to be utilized in high purity applications is preferably cleaned by electropolishing prior to installation. Additionally, subsequent to installation, metal tubing utilized in many industrial applications may be attacked on the inner tubular surfaces by chemicals passing through the tubing. This may result in the need to replace the tubing, at great cost. Significant cost savings can be accomplished in many industrial equipment applications, if the interior surface of the metal tubing can be cleaned, such that the tubing can be reused.
Prior art devices are known that can clean the Inner surface of straight tubing sections; however, tubing with a plurality of bends can pose a difficult problem. One such prior art device is described in U.S. Pat. No. 4,645,581, Apparatus for Electropolishing the Inner Surface of U-shaped Heat Exchanger Tubes, issued Feb. 24, 1987 to Voggenthaler et al. The present invention provides improved results.
Another problem which presents in the electropolishing of bent tubing, as well as tubing with extended straight runs, is keeping the tubing full of electrolyte solution during the electropolishing process. Gasses evolved by the electropolishing process accumulate and displace the electrolyte solution, thereby preventing the uniform electropolishing of the inner surface of the tubing. What is needed is a device that retains the electrolyte solution in the tubing, while facilitating the escape of the evolved gasses.